Optical discs for measuring analytes

ABSTRACT

This invention directs to an optical disc assembly configured to receive an analyte which can be detected by a standard optical disc reader or an optical disc reader modified therefrom. The optical disc assembly may preferably be designed so that the optical disc reader can track the disc and detect the analyte concurrently and discriminably. The optical disc assembly contains or encodes optically readable features which are trackable by the optical disc reader and which have encoded speed information enabling the optical disc reader to rotate the optical disc assembly at a determinable speed. The optical disc assembly also includes an analyte section capable of receiving the analyte that can be detected by the optical disc reader.

This application is a continuation of U.S. application Ser. No.11/458,335, filed Jul. 18, 2006 now U.S. Pat. No. 7,366,063, entitled“OPTICAL DISCS FOR MEASURING ANALYTES,” which is a continuation of U.S.application Ser. No. 10/005,313, filed on Dec. 7, 2001, now U.S. Pat.No. 7,079,468, entitled “OPTICAL DISCS FOR MEASURING ANALYTES,” whichclaims priority from U.S. Provisional Application Ser. No. 60/254,394,filed Dec. 8, 2000; U.S. Provisional Application Ser. No. 60/255,233,filed Dec. 12, 2000; U.S. Provisional Application Ser. No. 60/293,917,filed May 24, 2001; U.S. Provisional Application Ser. No. 60/294,051,filed May 29, 2001; U.S. Provisional Application Ser. No. 60/294,052,filed May 29, 2001; U.S. Provisional Application Ser. No. 60/303,437,filed Jul. 6, 2001; U.S. Provisional Application Ser. No. 60/306,226,filed Jul. 18, 2001; and U.S. Provisional Application Ser. No.60/323,405, filed Sep. 19, 2001, each of which are hereby expresslyincorporated by reference in their entireties.

FIELD OF THE INVENTION

This invention relates to optical discs configured to receive analyteswhich can be detected by a standard optical disc reader or an opticaldisc reader modified therefrom.

BACKGROUND OF THE INVENTION

Optical discs have been used for detection and characterization ofbiological and chemical samples. For instance, see WO 96/09548 (Gordon),EP A 392475 (Idemitsu), EP A 417 305 (Idemitsu), EP A 504432 (Idemitsu),and WO 98/12559 (Demers), all of which are incorporated herein byreference. Other examples of using optical discs to detectinvestigational samples can be found in U.S. Provisional Application60/252,725, entitled “Optical Bio-Disc Including Microfluidic CircuitFor Separation And Quantification Of Agglutinated Microparticles OrCells And Methods Relating Thereto,” U.S. Provisional Application No.60/252,726, entitled “Bioactive Solid Phase For Specific Cell CaptureAnd Optical Bio-Disc Including Same,” and U.S. Provisional ApplicationNo. 60/257,705, entitled “Surface Assembly For Immobilizing DNA CaptureProbes And Bead-Based Assay Including Optical Bio-Discs And MethodsRelating Thereto,” all of which are incorporated herein by reference.

These previously described optical discs, however, are not designed tobe read by standard optical disc readers, such as standard CD or DVDreaders. For instance, the optical discs disclosed in EP A 392475(Idemitsu), EP A 417 305 (Idemitsu) and EP A 504432 (Idemitsu) requirethe use of two optical detectors, one to detect the tracking informationand the other to detect surface structures. In contrast, reading astandard CD or DVD needs only one optical detector.

Therefore, there is a need to design and manufacture an optical discconfigured to receive an investigational sample which can be detected bya standard optical disc reader or an optical disc reader modifiedtherefrom.

Over the past decade, scanning laser microscopy (SLM) has revolutionizedlife science imaging. However, SLM demands expensive and specializedoptical equipment. Consequently, there exists a need to provide aninexpensive, generic device which can carry out laser scanning overmicroscopic specimens.

The present invention discovers that the minimum mechanical requirementsfor SLM, i.e. laser, focusing and detection optics, precision scanningmeans, and computer interface, may all be provided by a standard opticaldisc reader or an optical disc reader modified therefrom. Therefore, itis desirable to create an optical disc which can hold a microscopicsample that can be scanned by a standard optical disc reader. Such anoptical disc presents a marked advantage over existing SLM technologies.

In order for a standard optical disc reader to operate an optical disc,the optical disc reader is typically required to be able to (1)accurately focus above the operational surface of the optical disc, (2)accurately follow the spiral track or utilize some form of uniformradial movement across the optical disc surface, (3) recover enoughinformation to facilitate a form of speed control, such as CAV, CLV,VBR, CBR, or ZCLV, (4) maintain proper power control by logicalinformation gathered from the optical disc or by signal patternsdetected in the operational surface of the optical disc, and (5) respondto logic information that is used to control, for example, the positionof the objective assembly, the speed of rotation or the focusingposition of the laser beam.

A typical optical disc system uses elements of the optical medium itselfto satisfy at least some of these operational requirements. Forinstance, in a typical CD, the disc substrate is impressed with a spiraltrack made up of a series of embossed or impressed pits and lands. Lightreflected from these pits and lands can be used to generate signals.These signals are used by the optical disc reader to maintain properfocusing and tracking. In a CD-R disc, a wobble groove is used togenerate operational signals during disc recording. Dye marks arecreated during disc recording, and these dye marks may provide therequisite tracking structures during subsequent reading. Generally,under each of conventional optical disc standards, the structures thatencode data may simultaneously serve to provide operational signals thatenable an optical disc reader to operate the optical disc.

Conventional optical disc standards make no provision with respect toacquisition of information from investigational features, such asbiological or chemical specimens, that are disposed on the disc.Investigational features disposed on the disc may disrupt the trackingof the disc. In addition, investigational features may be sufficientlyseparated from operational structures, therefore preventing an opticaldisc reader from tracking the disc and detecting the investigationalfeatures concurrently and discriminably.

Therefore, there is a need to provide an optical disc which allows anoptical disc reader to detect the investigational features withoutdisrupting the tracking of the disc. There also exists a need to providean optical disc which allows an optical disc reader to track the discand read the investigational features concurrently and discriminably.

SUMMARY OF THE INVENTION

In one embodiment, an optical disc assembly is configured to associatewith an analyte which can be detected by a standard optical disc readeror an optical disc reader modified therefrom.

In another embodiment, an optical disc assembly is configured toassociate with an analyte, and the association with the analyte does notprevent an optical disc reader from tracking the disc assembly.

In yet another embodiment, an optical disc assembly, which is associatedwith an analyte, is configured to enable an optical disc reader to trackthe disc assembly and detect the analyte concurrently and discriminably.

In accordance with one aspect of this invention, the optical discassembly includes (1) optically readable structures which are trackableby an optical disc reader and which have encoded speed informationenabling the optical disc reader to rotate the optical disc at a speedthat is determinable from the speed information; and (2) an analytesection capable of receiving an analyte which can be detected by theoptical disc reader. The optically readable structures may be impressedin the operational surface and coated with a reflective layer. Theoptical disc reader may be a CD or DVD reader. The optically readablestructures can be in a CD format or a DVD format.

The analyte section may include at least one analyte chamber locatedwithin the disc assembly, such as between the operational layer andanother layer of the disc assembly. At least one channel may be createdin one of the layers of the disc assembly to allow the analyte or othercomponents to enter or exit the analyte chamber. The channel may includea valve regulated by optically readable data encoded in the optical discassembly. In one embodiment, the analyte section includes a plurality ofanalyte chambers, each chamber being connected to at least a channel.

In one embodiment, design information of the optical disc assembly isencoded in the disc assembly.

In another embodiment, the disc assembly is a reverse disc including alens layer capable of focusing the laser beam on the operational surfacewhich is located at the laser-proximal surface of the operational layer.

In yet another embodiment, the operational surface in the reverse discincludes a cut-away area which either lacks operational structures orincludes modified operational structures. In addition, the cut-away areamay lack reflective coatings.

In a preferred embodiment, the analyte chamber includes a surface whichis located within 15 micrometers from the operational surface,preferably located within 15 micrometers from the cut-away area, andwhich preferably is capable of receiving the analyte.

In another preferred embodiment, the disc assembly is a forward disc.The operational surface is at the laser-distal surface of theoperational layer and coated with a semi-transmissive, semi-reflectivelayer. There is a second layer which is laser-distal to the operationallayer and which is coated with another reflective layer. Preferably, theoperational surface includes a cut-away area, and the analyte chamberincludes a surface which is located within 15 micrometers from thecut-away area. More preferably, the analyte chamber includes thecut-away area. The second layer may lack optically readable structuresthat have encoded tracking information.

In one embodiment, the analyte section contains the analyte which may bea biological or chemical sample. Preferably, the analyte is locatedwithin 15 micrometers from the operational surface.

In yet another embodiment, the analyte section is embedded in the discassembly and includes a surface which is located within 15 micrometersfrom the operational surface and which preferably is capable ofreceiving the analyte.

In one embodiment, the disc assembly has encoded information forconducting an assay on the analyte.

In accordance with yet another aspect of this invention, the opticaldisc assembly includes (1) a hologram which contains optically readablefeatures that have encoded (a) tracking information, and (b) speedinformation enabling an optical disc reader to rotate the optical discat a speed that is determinable from the speed information; and (2) ananalyte section capable of receiving an analyte which can be detected bythe optical disc reader. The hologram may be reflective or replaceable.The optical disc reader may be a CD or DVD reader.

In one embodiment, at least part of the image plane of the hologram islocated within the analyte section. The analyte section may include theanalyte which may be positioned within 15 micrometers from the imageplane of the hologram. The laser beam may be focused on the image planeof the hologram.

In accordance with another aspect of this invention, an analyte held inthe analyte section of the optical disc assembly is detected using a CDor DVD reader. The detection includes the steps of (1) introducing theoptical disc assembly into the CD or DVD reader; (2) reading theoptically disc assembly; and (3) obtaining a signal which is indicativeof the presence of the analyte. Preferably, the signal thus obtained isa quad sum signal.

BRIEF DESCRIPTION OF THE DRAWINGS

All the drawings used herein are given by way of illustration, notlimitation, and all the drawing are not drawn to scale.

FIG. 1 demonstrates the functional components of an optical discassembly according to one embodiment of the present invention.

FIG. 2 shows a cross-sectional view of an optical stack including threelayers of refractive material.

FIG. 3 is a cross-sectional view of a compact disc recordable (CD-R)including a polycarbonate layer, a dye layer, and a reflective layer.

FIG. 4 is a diagram showing the geometry of a wobbled groove as it isembossed in an operational surface.

FIG. 5 shows a common arrangement of a reading laser beam relative to aspinning optical disc.

FIG. 6 shows wobbled grooves in a forward wobble optical disc, whereinthe wobble grooves are embossed in the laser-distal surface of theoperational layer.

FIG. 7 shows a forward wobble disc assembly containing wobbled groovescoated with a reflective layer, wherein the operational surface has acut-away area.

FIG. 8 shows a cross-sectional view of a forward wobble optical discassembly with an investigational feature placed on a cut-away area.

FIG. 9 demonstrates a reverse wobble optical disc assembly, wherein thewobble grooves are embossed in the laser-proximal surface of theoperational layer.

FIG. 10 presents a cross-sectional view of a reverse wobble discassembly with an investigational feature placed in the analyte section.

FIG. 11 compares the mastering process for making a forward disc withthe mastering process for making a reverse disc.

FIG. 12 further compares the mastering process for making a forward discto the mastering process for making a reverse disc.

FIG. 13 illustrates a reverse optical disc assembly.

FIG. 14 illustrates an optical pickup used in one embodiment of thepresent invention.

FIG. 15 depicts a quad detector used in one embodiment of the presentinvention.

FIG. 16 depicts the positions of investigational structures with respectto the tracks of operational structures.

FIG. 17 shows the HF signals acquired from the tracks illustrated inFIG. 16.

FIG. 18 shows an optical disc assembly including a gnat wing in aninspection channel.

FIG. 19 depicts the position of the gnat wing with respect to the tracksof the operational structures.

FIG. 20 shows the HF signals acquired from a track of the operationalstructures illustrated in FIG. 19.

FIG. 21 depicts the position of the gnat wing with respect to the tracksof the operational structures.

FIG. 22 demonstrates the HF signals acquired from a series ofconsecutive tracks of the operational structures illustrated in FIG. 21.

FIG. 23 depicts the position of the gnat wing with respect to the tracksof the operational structures.

FIG. 24 shows a high density compilation of the HF signals acquired fromthe tracks across the gnat wing.

FIG. 25 shows an objective lens focusing mechanism as used in oneembodiment of the present invention.

FIG. 26 illustrates an optical disc assembly containing a reflectivehologram.

FIG. 27 illustrates the data and surface organization of a zonedconstant linear velocity (ZCLV) format.

FIG. 28 shows an enlarged perspective view of a portion of a section ofa ZCLV disc, wherein the portion has a pre-groove area followed by awobble groove area.

FIG. 29 shows investigational features placed in a section in a ZCLVdisc.

FIG. 30 is an example of a forward disc, wherein the operationalstructures are coated with a semi-reflective layer, and investigationalfeatures are held laser-distal to the semi-reflective layer.

FIG. 31 shows a example of a forward disc which permits the laser lightto pass through the disc to a top detector.

FIG. 32 depicts a reverse optical disc assembly which includes fluidicchannels placed either above or below the operational surface.

FIG. 33 shows another reverse optical disc assembly in which theoperational surface has a cut-away area and fluidic channels are placedeither above or below the cut-away area.

FIG. 34 illustrates an example of a reverse optical disc assembly whichincludes channels and an analyte chamber.

FIG. 35 depicts a forward optical disc assembly which includes fluidicchannels placed either above or below the operational surface.

FIG. 36 shows another forward optical disc assembly in which theoperational surface has a cut-away area and fluidic channels are placedeither above or below the cut-away area.

FIG. 37 shows a forward optical disc assembly, wherein channels arecontained in a lens layer.

FIG. 38 shows a forward disc with channels placed above or below acut-away area.

FIG. 39 shows a forward disc assembly having a cut-away area.

FIG. 40 illustrates an exploded perspective of the principle layers in aforward disc assembly according to one embodiment of the presentinvention.

FIG. 41 shows a design of an operational layer.

FIG. 42 shows a design of an adhesive layer.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

This invention relates to an optical disc assembly configured to receivean analyte of interest which can be detected by an optical disc reader.The analyte of interest may be a physical specimen, such as abiological, chemical, or biochemical specimen, or a product produced bya biological or chemical reaction carried out in the optical discassembly. The optical disc reader may be a CD reader or a DVD reader.The optical disc reader may be a standard optical disc reader or anoptical disc reader modified therefrom. The optical disc assembly may bedesigned so that the association of the analyte with the disc assemblydoes not prevent the optical disc reader from tracking the disc assemblyor performing other operational functions.

As used herein, various surfaces in an optical disc assembly can benumbered or named according to the order in which the light beam of theoptical disc reader strikes or passes through them upon firstoccurrence. For example, when a compact disc (CD) is read by a CDreader, the laser beam of the CD reader first enters the disc through asurface of a polycarbonate layer. The polycarbonate layer also is knownas the polycarbonate disc or the substrate. This surface is referred toas the first surface or the laser-proximal surface of the polycarbonatelayer. The laser beam proceeds through the polycarbonate layer and comesout through another surface of the polycarbonate layer. This lattersurface is referred to as the second or the laser-distal surface of thepolycarbonate layer. The laser beam proceeds to a reflective layer whichis usually made of gold or other reflective material. The reflectivelayer is laser-distal to the polycarbonate layer. The laser beam isreflected back from the reflective layer, passing through thepolycarbonate layer and entering a detector in the CD reader.

When a CD-R disc is read by a CD-R reader, the laser beam of the readerenters the CD-R disc through the first surface of a polycarbonate layer.The laser beam proceeds through the polycarbonate layer and enters intoa dye layer which is laid on the tracks embossed or impressed in thelaser-distal surface of the polycarbonate layer. The polycarbonate layeris laser-proximal to the dye layer. The back surface of a CD-R disc,upon which labels or markings are laid, is referred to as the backplane. The back plane is the most laser-distal surface in the CD-R disc.

As used herein, “operational structures” or “operational features” in anoptical disc assembly refer to optically readable structures which areimpressed or encoded in the optical disc assembly and which enable anoptical disc reader to track, synchronize, or perform other customizedoperational functions. Operational structures may act as phasecomponents or provide interference patterns. Operational structures mayhave encoded speed information that enables the optical disc reader torotate the disc assembly at a speed determinable from the speedinformation. Light returned from or passed over operational structurescan be acquired by the optical disc reader to generate operationalsignals. These operational signals are used by the optical disc readerto track, focus, synchronize, or perform other operational functions.

Operational structures may be imprinted or impressed in a surface of alayer in the disc assembly. Such a layer is referred to as an“operational layer,” and such a surface is referred to as an“operational surface.” In a typical CD disc, the operational layer isthe polycarbonate disc, and the operational surface is the laser-distalsurface of the polycarbonate disc. An optical disc assembly may havemore than one operational layer or operational surface. Preferredoperational structures include, but are not limited to, wobble grooves,pits and lands, dye marks, or any combination thereof.

Operational structures may be encoded in a hologram. Light returned fromor transmitted through the hologram can create an image plane withinwhich the encoded operational structures appear to be positioned. Theencoded operational structures, as appeared in the image plane of thehologram, preferably are in the form of wobble grooves, tracks of pitsand lands, or any other type of operational structures that may bephysically impressed in an optical disc's operational layer.

Operational structures, impressed or encoded, may be in a variety offormats. Suitable formats for this invention include, but are notlimited to, CD formats, DVD formats, any combination thereof, or otheroptical disc formats. CD formats include, but are not limited to,CD-ROM, CD-R and CD-RW formats. DVD formats include, but are not limitedto, DVD-R, DVD-RW and DVD-RAM formats. As appreciated by one of skill inthe art, other CD or DVD formats or other optical disc formats,including those that have been or will be developed in the future, maybe used in the present invention.

“Investigational structures” or “investigational features” refers to thestructures, features or items that are placed in an optical discassembly to be examined. An investigational structure or feature may bean analyte which includes a physical specimen, such as a biological orchemical sample, or a product produced by a biological or chemicalreaction conducted in the optical disc assembly. An investigationalstructure or feature may also be part of an analyte. Investigationalstructures or features usually cannot provide operational information.Investigational structures or features typically are not imprinted orimpressed in the optical disc assembly. They usually are not encoded ina hologram. Preferably, investigational structures or features arereplaceably disposed in the optical disc assembly. Investigationalstructures or features may be chemical, biochemical, or biological innature. They may also be signal or reporter elements such as beads.

Association of investigational structures with an optical disc assemblyof the present invention does not prevent the optical disc reader fromoperating the optical disc assembly. In order to operate an optical discassembly, the optical disc reader usually needs to (1) accurately focusabove the operational surface of the disc assembly, (2) accurately trackthe operational surface or use some form of radial movement across thedisc surface, (3) maintain a form of speed control, (4) maintain properpower control by logical information gathered from the disc assembly,and (5) respond to logic information that may be used to control, forexample, the position of the objective assembly, the speed of rotation,or the focusing position of the laser beam.

An analyte that is disposed in the optical disc assembly of the presentinvention can be read or detected by an optical disc reader. As usedherein, an analyte can be read or detected by an optical disc reader ifthe optical disc reader can generate at least a signal indicative of thepresence of the analyte. The present invention also contemplates the useof the optical disc reader to generate signals indicative of otherproperties of the analyte, such as the concentration or dimension of theanalyte.

In accordance with one aspect of the present invention, the optical discassembly includes at least an operational layer and at least an analytesection. The operational layer contains an operational surface in whichoperational structures are impressed. The operational structures haveencoded operational information which enables the optical disc reader tooperate the disc assembly. In particular, the operational structures mayhave encoded tracking information that allows the disc reader to trackthe operational structures. The operational structures may also haveencoded speed information enabling the disc reader to rotate the discassembly at a speed determinable from the encoded speed information.Preferably, the operational structures are coated with a reflectivelayer containing a reflective material, such as metal, aluminum, gold,silver, or silicon. As used herein, a reflective layer can besemi-reflective and semi-transmissive. Light reflected from thereflective layer can be acquired by the disc reader to generateoperational signals for focusing, tracking, or performing otheroperational functions. The operational layer may be a hologram in whichthe operational structures are encoded.

Speed information encoded in the operational structures allows anoptical disc reader to rotate the optical disc assembly at adeterminable speed. Speed information may be encoded in framesynchronization words which allow the optical disc reader to adjust thedisc speed to keep a desired data rate. The speed information may alsobe encoded in a wobble groove. The wobble groove can produce signalsuseful for regulating the disc speed. In addition, special marks orlogic information can be used to provide speed information. In oneembodiment, the optical disc reader rotates the optical disc assemblywith a constant linear velocity.

The analyte section is configured to receive at least an analyte ofinterest. The analyte section may be embedded in the disc assembly. Itmay be positioned between two layers of the disc assembly. It may alsobe located within a layer in the optical disc assembly. As used herein,a layer in a disc assembly refers to a thickness of material. Forinstance, a layer may be a substrate disc or a coating of reflectivematerial. A layer may also be an insert which can be assembled intoanother layer in the disc assembly. A layer may be flat or not flat. Alayer may be homogeneous or non-homogenous. The depth of a layer may beuniform or not uniform. A layer may be an assembly of several parts. Theanalyte section may be the most laser-distal or the most laser proximalstructure in the disc assembly. The analyte section may includechannels, microfluidic channels, chambers, cavities, or other structuresthat are designed for the manipulation, creation, or retention of theanalyte of interest or the investigational structure. The analytesection may also be referred to as the component layer. An optical discassembly may have more than one analyte section. The analyte section andthe operational layer can be intermixed so long as the optical discreader can retain control of focusing, tracking, velocity and otheroperational functions. Analytes or investigational structures can be inthe nanometer, micrometer or millimeter range, and can be disposed,modified or created in the analyte section.

Preferably, the optical disc assembly includes a lens layer. The lenslayer may be used to focus the laser beam, for instance, on either theoperational structures, or the investigational structures. In oneembodiment, the operational layer may function as a lens layer. In sucha case, the operational structures are embossed in the laser-distalsurface of the operational layer. The refractive index of the lens layercan be selected to perform the desired focusing function. The lens layertypically is laser-proximal to the operational or investigationalstructures. Preferably, the lens layer includes a material selected fromthe group consisting of plastic and glass. More preferably, the lenslayer consists of plastic, such as polycarbonate or polystyrene. In ahighly preferred embodiment, the lens layer consists of polycarbonate.Other examples of material suitable for constructing a lens layerinclude polymethylacrylic, polyethylene, polypropylene, polyacrylate,polymethyl-methacrylate, polyvinylchloride, polytetrafluoroethylene,polyacetal, polysulfone, celluloseacetate, cellulosenitrate,nitrocellulose, or any mixtures or combinations thereof.

The optical disc assembly of the present invention preferablyapproximates the dimensions of a unitary disc. For instance, the discassembly may have a radial diameter between about 110 mm and 130 mm,including the range from 75 mm to 85 mm, and preferably 120 mm.Preferably, the disc assembly has a depth or thickness between about 0.8mm and 2.4 mm, such as between 1.0 mm and 1.4 mm. More preferably, thedisc assembly has a depth or thickness between 1.1 mm and 1.3 mm,including 1.2 mm. In one embodiment, the disc assembly may have athickness of about 0.6 mm. The disc assembly may be flat or not flat,circular or non-circular. The disc assembly may have a central holethrough which the disc assembly can be coupled to a disc reader.

With reference to FIG. 1, there is shown a diagram illustrating oneembodiment of the present invention. The optical disc assembly has atleast an operational layer 338, a component layer 336, and a lens layer340. The disc assembly encompasses the focusing range of the laser usedby the disc reader. The operational layer 338 contains the operationalstructures that are used by the disc reader to track the disc assembly.The operational structures may create an interference pattern or otherpatterns that provide operational functionality to the disc reader. Thecomponent layer 336 contains the investigational structures as well asother structures that are related to the manipulation, creation, orretention of the investigational structures. The component layer mayinclude microfluidic channels. The lens layer 340 may focus the laserbeam either on the operational structures or on the investigationalstructures. The component layer and the operational layer may beintermixed or overlapped so long as the disc reader can retain controlof the focusing, tracking and speed. The measurement area 342 representsthe area which are readable by the disc reader's laser, and the laser'sfocal point can roam across the measurement area. The measurement areamay encompass any of the component layer, the operational layer, thelens layer, or a portion thereof.

Different layers in an optical disc assembly may have different opticalproperties and can impose different optical effects on the light beamthat passes through these layers. These optical effects include, forexample, reflection, refraction, transmission, or absorption. FIG. 2 isa simplified example showing the effects of different layers on thepassage of a light beam.

The optical disc 102 in FIG. 2 includes three layers of refractivematerial, 104, 106 and 108. The refractive properties of these layersmay differ based on their compositions. The different refractiveproperties create changes in the light beam 110 as the light beam passesthrough these layers. The layers may be named in order of their firstcontact with the light beam 110. The light beam 110 enters through thebottom surface 112 and exits at the top surface 118. Therefore, layer104 may be referred to as the most laser-proximal layer, and layer 108as the most laser-distal layer. Layer 106 is laser-distal to layer 104,and laser-proximal to layer 108.

The light beam 110 enters layer 104 at surface 112. The light beam isbent and slowed because of the refractive property of layer 104. Thelight beam exits layer 104 at surface 114, and then enters layer 106which has a different refractive property, therefore further alteringthe angle and speed of the light beam. As the light beam exits layer106, it enters layer 108 at surface 116 with a further changed angle andspeed. The light beam exits layer 108 at surface 118. Surface 112 islaser-proximal to surface 114 which is laser-proximal to surface 116.Surface 118 is the most laser-distal surface in the optical stack 102.

In one embodiment, the optical disc assembly is designed based on amodification of an industry standard design, such as standard CD(including CD-R and CD-RW) or a standard DVD (including DVD-RAM, DVD-Rand DVD-RW). The following description is based on modifications of astandard CD-R disc. Similar modifications can be applied to otheroptical discs, such as CD-RW or DVD discs, as appreciated by one ofordinary skill in the art.

A normal CD-R disc contains a wobble groove utilized by the CD-R driveto spin and track the disc. A similar principal applies to a DVD-typedisc. A standard CD-R disc has a polycarbonate operational layer havinga depth of about 1.2 mm. The polycarbonate operational layer has atleast a wobble groove embossed in the laser-distal surface of the layer.The depth of the wobble groove in a standard CD-R is approximately from165 nanometers to 230 nanometers. A typical wobble groove is filled withdye. Above the dye layer is a reflective layer which contains gold orother reflective material such as silver. The reflective layer canreflect the laser beam of the disc drive back to a detector in the discdrive. The laser beam can be focused on the reflective layer. Thelaser's focus may be adjusted by a focusing servo. The wobble groovefunctions like a diffraction grating, and is capable of creating apattern in the reflected laser light. The pattern in the reflected laserlight is used by the disc drive to spin and track the disc. In astandard DVD disc, the wobble groove depth can be 50 nanometers.

FIG. 3 exemplifies a CD-R disc with an industry standard design. Thedisc has an operational layer 120 which is usually made ofpolycarbonate, a dye layer 122 which contains CD recordable lightsensitive dye, and a reflective layer 124 which contains gold, silver orother material that is suitable for reflecting the laser beam 128 backto the detector of the disc drive. The operational layer 120 is capableof focusing the laser beam 128 on the reflective layer 124. As usedherein, a layer in an optical disc is capable of focusing a reading beamof an optical disc reader on an object if the reading beam, which isdirected to the object, can pass through the layer and become focused onthe object while the optical disc reader is operating the optical disc.Preferably, the refractive index of the layer is significantly greaterthan the refractive index of air, as appreciated by one of skill in theart. For instance, the refractive index of the layer may be 1.55. Otherlayer or layers may also exist in the optical path of the reading beamto help the reading beam become focused on the object. The wobble groove126 is shown in FIG. 3.

FIG. 4 demonstrates the geometry of a wobbled groove in a CD-R. As withother figures used herein, FIG. 4 is not drawn to scale. The wobblegroove is usually embossed into the laser-distal surface of theoperational layer in a CD-R. FIG. 4 shows two wobbled grooves.Measurement A, 132, represents the distance between two adjacent wobblegrooves. Measurement B, 134, denotes the width of the top of the wobblegroove. Measurement C, 136, represents the width of the bottom of thewobble groove. Measurement D, 138, shows the depth of the groove. Theangle E, 140, between the side-wall 142 and the bottom of the wobblegroove has an important effect on light that encounters the wobbledgroove. The geometry of the wobble groove in a CD-R disc has asignificant effect on the performance of the CD-R disc in a high speedwriter.

An optical disc spins in a disc reader clockwise when looking down onthe disc. From the viewpoint of the reader's laser (looking up),however, the disc is spinning counter-clockwise. FIG. 5 demonstrates acommon arrangement of an optical disc in a disc drive. The samearrangement can be employed in the present invention. The laser beam 146is directed to the optical disc 144 from below. The optical disc 144spins in a counter-clockwise direction 148 as seen from below the disc.From above the disc, however, the disc 144 spins in a clockwisedirection.

The optical disc of the present invention may be designed based onmodifications of a standard CD-R disc. The standard CD-R disc is a“forward” disc, in which the operational structure is positioned at thelaser-distal surface of the operational layer. Whereas the operationalstructure of a forward disc is a wobble groove, the disc is alsoreferred to as a “forward wobble” disc. A forward wobble disc has itswobble groove positioned on the second surface or the laser distalsurface of the operational layer.

FIG. 6 illustrates a forward disc 150. Laser beam 152 enters theoperational layer 158 at its first or laser-proximal surface 154. Thelight is bent according to the refractive property of layer 158. Thefocus of the laser beam 152 encompasses the bottom of wobble groove 160.Wobble groove 160 is embossed in the second or laser-distal surface 156of layer 158. Reference numeral 159 denotes a land of the wobble groove.

FIGS. 7 and 8 illustrate the forward discs that may be employed in thepresent invention. The forward optical disc assembly 224 in FIG. 7includes an operational layer 226 which has wobble grooves in itslaser-distal surface. The wobble grooves are coated with a reflectivelayer 228 containing reflective material, such as gold. The reflectivelayer 228 may be semi-reflective. The operational surface has a cutawayarea at location 229 which allows laser light 230 to pass through thewobble grooves and reach another reflective layer 232. The reflectivelayer 232, which contains reflective material, can be deposited on a topcover layer 234 which can provide a stable surface for the reflectivelayer 232. Assembly 224 also has an analyte section 236 which isconfigured to receive analytes of interest. The tracking of the disc isperformed by the laser beam 230 when it encounters the reflective layer228 that covers the wobble grooves. The size and configuration of thecut-away portion 229 is calculated to allow the laser to resume trackingbefore control of the disc is lost by the disc drive's trackingmechanism. The reflective layer 232 permits the laser beam to return toa detector in the disc reader after the laser beam passes through thecut-away portion 229 to the analyte section 236.

As used herein, a “cut-away” area refers to an area in the operationalsurface, wherein the area either lacks operational structures or theoperational structures in the area are changed in certain ways. Theoperational structures in a cut-away area may be deprived of reflectivecoatings, or be coated with a reflective material having a differentreflectivity than the reflective material coated on other regions in theoperational surface. In a preferred embodiment, one surface of theanalyte section is adjacent to a cut-away area, or includes a cut-awayarea.

FIG. 8 shows another forward optical disc which includes aninvestigational structure 354. The operational layer 344 contains theoperational structures which are embossed at its laser-distal surfaceand coated with a reflective layer 350. The operational layer serves asa lens layer and can focus the laser beam 352 on the operationalstructures. The analyte section 346 is configured to hold aninvestigational structure 354, which is within the focal zone 356 of theoptical disc reader's laser. The laser beam 352 may pass through acut-away area 348 and be focused on the investigational structure 354.The cut-away area lacks the reflective coating. The disc assembly has asecond reflective layer 360 which is laser-distal to the operationalstructures and capable of reflecting laser light. The cover 358 islaser-distal to the second reflective layer. The analyte section 346contains the cut-away area 348 upon which the investigational structure354 is positioned.

As used herein, a laser's focal zone refers to the range of distancewithin which the laser's focal point may be positioned. In a standard CDdrive, the laser's focal zone is about 25 to 26 micrometers. Thus, thelaser's focal point can move above and below a trackable surface in arange of about 12.5 to 13 micrometers. Some variations (about ±2micrometers) are allowed for the movement. Accordingly, in a preferredembodiment, the analyte section is capable of positioning an analyte atleast within about 15 micrometers from the trackable surface in orderfor the laser reading beam of the optical disc reader to be focused onthe analyte. When a hologram is used to encode operational structures,the analyte preferably is located within about 15 micrometers from theimage plane of the hologram. In one embodiment, a surface of the analytesection is located within about 15 micrometers from the trackablesurface or the image plane of the hologram. The surface of the analytesection may also be capable of receiving the analyte. The surface of theanalyte section may be part of a larger surface of the analyte section.The 15 micrometers limitation may be modified in a modified optical discreader.

In a preferred embodiment, the optical disc assembly employs a spiralwobble groove to provide operational signals. As used herein, a spiralwobble groove can be considered as a series of wobble grooves connectedconsecutively to form a spiral track. The depth of the wobble groove ispreferably from 50 to 100 nanometers, including 65 nanometers, 70nanometers, 73 nanometers and 100 nanometers. More preferably, the depthof the wobble groove is approximately ⅛ of the effective wavelength ofthe laser light in the layer which is immediately laser-proximal to theoperational surface. Such a depth may provide a strong tracking signal.The groove may also have a depth approximately equal to any odd multipleof ⅛th of the wavelength, such as ⅜ths or ⅝ths. The depth of the groovemay remain substantially constant along the wobble groove. The periodicperturbation of the wobble provides the information for tracking. In oneembodiment, the spiral groove has a track pitch of approximately 1.6microns.

Preferably, no dye is laid down in the wobble groove, or the dye is laiddown in discrete patterns so as to facilitate drive control during theexamination of investigational features. The present invention discoversthat a conventional CD-R wobble groove without dye is readable by astandard optical disc reader. The groove can be coated with a layer ofreflective material, such as gold, or semi-reflective material. Thereflective layer preferably is positioned sufficiently close to thegroove structure so as to provide adequate reflection when the laserlight focuses on the groove structure. In addition, the pitch and angleof the groove walls can be selected to facilitate the detection ofinvestigational features which are placed on or between various surfacesor layers in the disc.

In accordance with one aspect of the present invention, the optical discassembly is a “reverse” disc. The operational structures in a reversedisc are imprinted or impressed in the laser-proximal surface of theoperational layer. When the operational structure is a wobble groove,the reverse disc may also be referred to as a “reverse wobble” disc. Areverse wobble disc has the wobble groove impressed in the laserproximal surface of the operational layer. A standard CD-R disc has thewobble groove impressed in the laser-distal surface of the operationallayer.

FIG. 9 depicts a reverse wobble disc assembly 162. The reverse wobbledisc assembly 162 includes an operational layer 164 and a cover 166. Theoperational layer 164 is further shown in an enlarged view 168. Cover170 represents the enlarged view of cover 166. Cover 170 provides themost laser-proximal layer in the disc assembly. The laser beam 172enters cover 170 at its laser-proximal surface 174. The laser beam atsurface 174 is bent due to the refractive property of cover 170. Thelaser exits the cover and is focused on the wobble groove 176 which isembossed in the laser-proximal surface 178 of the operational layer 168.The laser may or may not pass through the wobble groove to reach otherlayers.

FIG. 10 shows a reverse wobble disc containing an investigationalstructure. The cover 362 acts as a lens to focus the laser beam 364 ontothe operational structures. The laser beam 364 may also be focused onthe investigational structure 366, depending the reflectivity of theinvestigational structure 366. The investigational structure 366 is heldin the analyte section 372 which is between the operational layer 370and the cover layer 362. The analyte section 372 lies within the laser'sfocal zone 368 which also encompasses the operational surface. Theoperational structures are covered by a reflective layer 374.

The process for manufacturing a reverse wobble disc is different fromthe process for making an industry standard forward wobble disc. FIGS.11 and 12 demonstrate the difference between making a reverse wobbledisc and making a forward wobble disc. The process for making a normal,forward wobble CD-R is shown at 188, whereas the process for making areverse wobble disc is shown at 190. In both cases, a master 192 ismade. A father stamper 194 is made from master 192, as appreciated byone of skill in the art. A mother 196 is made from the father stamper194. The image embossed in the mother 196 is thus a duplicate of theoriginal master 192. To make a forward wobble disc, a son stamper 198 isfurther made from the mother 196. The son stamper 198 has an imageidentical to that of the father stamper 194. A forward wobble disc, asshown in FIG. 12, is then made from the son stamper 198. In contrast, areverse wobble disc 202 is made from the mother stamper.

FIG. 12 further illustrates the difference between manufacturing aforward wobble disc and manufacturing a reverse wobble disc. The sonstamper 198′ is identical to the son stamper 198 in FIG. 11. The sonstamper 198′ is used to create a wobble groove on the laser-distalsurface 208 of the substrate layer 204, therefore creating a forwardwobble disc. Surface 208 may be coated with a dye layer 210 which isfurther layered with a reflective coating 212. Preferably, the surface208 is directly coated with the reflective coating 212 without the dyelayer 210. The laser beam of the disc reader can travel through the mostlaser-proximal surface 206 and then the operational layer 204 to reachthe surface 208. The surface 208 is the operational surface.

In comparison, the reverse wobble discs 214 and 202′ are made from themother stamper. The wobble groove in the reverse wobble disc 214 ispositioned at the first or laser-proximal surface of the operationallayer 216. Surface 218 is the second or laser-distal surface of theoperational layer 216. The cover 222 is capable of focusing the laserbeam on the wobble groove. To facilitate the reading of the wobblegroove, a reflective layer 220 is deposited on the first surface oflayer 216. The first surface of layer 216 is the operational surface. Asviewed from the optical pick of the optical disc reader, the operationalsurface of the reverse wobble disc 214 appears to have the same image asthe operational surface 208 of the forward wobble disc.

A reverse wobble disc can be manufactured so that the spiral of thewobble groove moves from the inner diameter of the disc to the outerdiameter of the disc when the disc is spun counter-clockwise as viewedfrom the laser. This configuration is the same as used by a conventionalforward wobble disc.

In another embodiment, a reverse wobble disc can be prepared using aprocess similar to process 190 in FIG. 11. However, the wobble groove inthe master disc has a reverse image of the wobble groove in the masterdisc 192. The reverse wobble disc thus prepared has the wobble grooveimpressed at the laser-proximal surface of its operational layer. Astandard CD-R or CD-RW reader can track both the reverse wobble disc ofthis embodiment and the reverse wobble disc manufactured using themaster disc 192. The disc tracking is dependent upon the frequency ofthe wobble. Likewise, a forward wobble disc can be created using process188 but with a master disc having a reverse image of the master disc192.

FIG. 13 demonstrates a reverse disc according to one embodiment of thepresent invention. The reverse disc 240 includes an operational layer242 which contains a wobble groove 250 at its laser-proximal surface.The wobble groove 250 is coated with a reflective layer 248 whichcontains reflective material, such as gold. The laser beam 246 can befocused by the cover 244 upon the wobble grove 250 or upon thereflective layer 248. The assembly 240 permits investigationalstructures to be placed in the analyte section 252 and to be examined bythe laser beam 246.

For more information about optical discs in which operational structuresare positioned in the laser-proximal surface of the operational layer,see U.S. patent application Ser. No. 09/421,870, entitled “TrackableOptical Discs With Concurrently Readable Analyte Material,” which isincorporated herein by reference.

In accordance with one aspect of the present invention, various types ofdata or information can be digitally encoded in the disc assembly. Thesedata or information may be encoded in accordance with industrystandards, such as CD or DVD standards, or standards modified therefrom.These encoded data or information may control or facilitate an opticaldisc reader to track the disc assembly or detect investigationalstructures that are disposed in the disc assembly.

Investigational structures that are disposed in an optical disc assemblycan be read or detected using an optical disc reader, such as a CDreader or a DVD reader. As used herein, CD readers include, but are notlimited to, CD-ROM readers, CD Recordable (CD-R) readers, CD-Rewriteable(CD-RW) readers, or any reader capable of reading CD-format discs.Industry standard CD readers may be used in the present invention.Preferably, a standard CD-RW reader or a modification thereof is used inthe present invention. As used herein, DVD readers include, but are notlimited to, DVD-R readers, DVD-RAM readers, DVD-RW readers, or anyreader that can read DVD-format discs. Industry standard DVD readers maybe used. As appreciated by one of skill in the art, other CD readers,DVD readers or optical disc readers, including those that have been orwill be developed in the future, may be used in the present invention.An optical disc reader may read both CD and DVD discs.

Signals indicative of the presence or other properties of aninvestigational structure can be generated by an optical disc reader.The disc reader directs a reading beam of electromagnetic radiation,typically a laser beam, to the optical disc assembly in which theinvestigational structure is disposed. The disc reader can scan the beamover the area in which the investigational structure is held. Thescanning beam can be either reflected from or transmitted through thedisc assembly. The reflected or transmitted radiation may be acquired bya detector in the disc reader. Radiation thus acquired can be used toproduce signals indicative of the presence or other properties of theinvestigational structure. Different types of lasers with differentwavelengths may be used in the present invention. Whereas a standardoptical disc reader is used, the disc reader may be connected tocircuitry for processing the signals indicative of the presence or otherproperties of the investigational structure.

Radiation acquired by the detector of the optical disc reader can alsobe used to generate operational signals, such as focusing servo signals,tracking servo signals, synchronization signals, power control signals,and logic signals. The focusing servo signals can be generated from atleast three focusing techniques: critical angle focusing, knife edgefocusing and preferably, astigmatic focusing. Tracking servo signals canbe generated from at least four types of tracking techniques: onebeam-push-pull tracking, three beam outrigger tracking, differentialphase detection tracking, and one beam high frequency wobble tracking.Synchronization signals may be generated from at least three differentmethods: bit clock synchronization or bit pattern synchronization, zonedclocking method, and wobbling groove synchronization. Logic signals canbe produced from various optical disc formats. Logic signals can be usedto perform position sensing, power control, radial and tangentiallocation, layer sensing, density detection, or other functions.

Preferably, the optical pickup of a standard CD reader is used to bothtrack the optical disc assembly and detect the investigational structuredisposed therein. FIG. 14 illustrates an example of the optical pickupof a standard CD reader. The optical pickup 254 contains a laser source260, which typically is a laser diode. The laser source emits a laserbeam 262. The laser beam is collimated by a collimator lens 264. Thecollimated beam is then directed toward the optical disc through apolarization beam splitter 266. The objective lens 268 focuses the laserbeam onto a small spot on a surface in the optical disc. In FIG. 14, thesurface is the operational surface of a CD-type optical disc, whichcontains pits and lands 256. The surface preferably is coated with areflective layer, so that the laser beam can be reflected therefrom andthen directed by the objective lens 268, the mirror 270 and the quarterwave plate 272 to the beam splitter 266. As the light is now polarizedin a different direction as compared to the source polarization, it canbe directed by the beam splitter towards a photodiode detector 274. Acylindrical lens 276 may serve as an astigmatic element to introduceastigmatism in the reflected laser beam for the purpose of focusing.

In a preferred embodiment, the laser beam is split into three beams,consisting of a main beam and two tracking beams, and the detector is aquad detector. FIG. 15 shows a quad detector 278, which includes acentral quad detector 280 flanked by two additional sensor elements E281 and F 282. The main beam is centered on a track defined by pits in aCD-ROM disc. The tracking beams fall on either side of the track. Bydesign, the three beams are reflected from the optical disc and thendirected to the quad detector 278 such that the main beam falls on thecentral quad detector 280, which includes sensor elements A, B, C, andD, while the tracking beams fall on the sensor elements E 281 and F 282.The sum of the signals from the central quad detector, i.e. A+B+C+D,provides the radio frequency (RF) signal 284, also referred to as thehigh frequency (HF) or the quad-sum signal. A tracking error signal (TEsignal) 288 may be obtained from the difference between E and F. Becauseastigmatism is introduced by the cylindrical lens astigmatic element, afocus error signal (FE signal) 286 may be obtained from the differencebetween A+C and B+D signals. Other combinations of the signals from Athrough F may be obtainable, as appreciated by one of ordinary skill inthe art. These combinations of signals may be used to track the disc andread the investigational structure disposed in the disc. A quad detectorand a similar optical design may be employed in a DVD reader.

In one embodiment, the quad-sum signal is used for extractinginformation indicative of the presence or other properties of theinvestigational structure disposed in the disc assembly. Preferably, thedisc assembly contains a wobble groove which is trackable by a discreader. Suitable disc readers include CD-R readers, CD-RW readers or DVDreaders. The use of the wobble groove enables the segregation of thetracking signal from the quad sum signal, permitting the quad sum signalto be used to detect signals from investigational structures. If theinvestigational structure is small enough, an electrical deflection maybe detected in the quad-sum signal, while no such a deflection, or acomparatively smaller electrical impulse, will be noted in the trackingsignal or the focusing servo signal.

A large investigational feature may also be detected by using thequad-sum signal without losing the tracking of the disc assembly. Insuch a case, a forward disc, such as that shown in FIGS. 31 and 37, ispreferably used. The ability of an operational structure, such as thewobble groove, to permit both disc tracking and analyte detection isherein referred to as segregation of tracking from investigationalstructures.

The signals produced from a wobble groove can be used by the disc readerto maintain a constant linear scanning velocity at all points on thedisc. This allows determination of the dimensional information of theinvestigational structure that is placed in the disc. Therefore, wobblegroove is a preferred operational structure employed in this invention.

Although the above-described embodiment uses the quad-sum signal and thewobble groove, signals other than the quad-sum signal and operationalstructures other than the wobble groove may be used for the detection ofinvestigational structures. For instance, the focus error signalobtained by the critical angle method, as described in U.S. Pat. No.5,629,514, may be used. The Foucault and astigmatism methods, asdescribed in “The Compact Disc Handbook,” by Pohlmann, A-R Editions,Inc. (1992), may also be employed. In addition, the tracking errorsignals obtained using the single beam push-pull method as described in“The Compact Disc Handbook,” by Pohlmann, A-R Editions, Inc. (1992), thedifferential phase method as described in U.S. Pat. No. 5,130,963, orthe single beam high frequency wobble method can be used for the presentinvention. The block error rate information, such as those used by a CDreader to reduce the effect of scratches on a CD surface, or themovement of the focusing servo may be used.

For more optical pickup designs and operational signals that may be usedin the present invention, see “Compact Disc Technology,” by Nakajima andOgawa, IOS Press, Inc. (1992); “The Compact Disc Handbook,” by Pohlmann,A-R Editions, Inc. (1992); “Digital Audio and Compact Disc Technology,”by Baert et al. (eds.), Books Britain (1995); “CD-Rom Professional'sCD-Recordable Handbook: The Complete Guide to Practical Desktop CD,”Starrett et al. (eds.), ISBN: 0910965188 (1996). All these referencesare incorporated herein in their entirety by reference.

U.S. Provisional Application Ser. Nos. 60/270,095 and 60/292,108 furtherdetail how to extract or process signals indicative of the presence ofan investigational structure disposed in an optical disc assembly. Bothapplications are incorporated herein by reference.

FIG. 16 and FIG. 17 illustrate a measurement of investigationalstructures using an optical disc assembly according to one embodiment ofthe present invention. The analyte section is laser-proximal to theoperational layer, and is positioned between the operational surface anda lens layer. FIG. 16 depicts the position of the investigationalstructures 800 with respect to the tracks 802, 804, 806 and 808. Theinvestigational structures 800 are held in the analyte section andpositioned on the operational surface. The investigational structures800 are 2.8 micrometer magnetic beads. Tracks 802, 804, 806 and 808 areembossed in the operational surface. Each track preferably is in theform of a wobble groove.

FIG. 17 shows the HF signals 802′, 804′, 806′ and 808′ that are acquiredalong the tracks 802, 804, 806 and 808, respectively. The HF signalsshown in FIG. 17 have been digitalized and buffered. The HF signals802′, 804′, 806′ and 808′ demonstrate the existence as well as theapproximate dimension of the investigational structures 800.

FIGS. 18 through 24 illustrate the measurement of a gnat wing disposedin an optical disc assembly. FIG. 18 is a cross-sectional view takenperpendicular to a radius of the optical disc assembly. In FIG. 18, theoptical disc assembly includes an operational layer 814, a firstreflective layer 816, a second reflective layer 810 and a cover 812. Theanalyte section 826 is located between the second reflective layer 810and the operational layer 814. The operational surface 818 is thelaser-distal surface of the operational layer 814. The operationalsurface 818 is embossed with tracks of operational structures,preferably, wobble grooves. The operational surface 818 is covered bythe reflective layer 816. The operational surface has a cut-away area824 which may lack the reflective coating 816. The gnat wing 822 islocated in the analyte section 826 and positioned upon the cut-away area824. The laser beam 820 can pass through the operational layer 814, thecut-away area 824 and the gnat wing 822, and then be reflected by thereflective layer 810.

FIG. 19 diagrammatically shows the position of the gnat wing 822relative to the tracks embossed in the operational surface. T1 denotes atrack upon which the gnat wing is positioned. FIG. 20 shows the HFsignal acquired along the track T1. The HF signal has been digitalizedand buffered.

In FIG. 19, the Y-axis, labeled with “TRACKS,” represents the number oftracks along a radius of the disc assembly. The X-axis, labeled with“TIME (SAMPLES),” represents the number of sampling along a track. Forinstance, the gnat wing can be sampled by the disc reader along thetrack T1 at least about 800 times (from sample number 1550 to samplenumber 2350).

FIG. 21 shows the position of the gnat wing 822 relative to the tracksT2 and T3. FIG. 22 demonstrates the HF signals for a series ofconsecutive tracks between T2 and T3.

FIG. 24 is a high density compilation of the HF signals for the tracksacross the gnat wing. The image of the gnat wing appears in FIG. 24.FIG. 23 shows the position of the gnat wing 822 relative to the tracks.

In accordance with another aspect of the present invention, the opticaldisc reader includes an objective lens focusing mechanism which iscapable of focusing the disc reader's laser onto different surfaces inthe disc assembly. In one embodiment, the focusing servo 290 shown inFIG. 25 includes a coil and magnet casing surrounding the objectivelens. The objective lens 292 directs the laser 294 onto the surface 296of the disc. Then the laser light travels through a lens layer, andfocuses onto the operational surface 298. The operational surfacecontains operational structures, such as wobble grooves, or pits andlands. The objective lens is held by a brace 302 which is part of themoving coil controlled by the magnet 306. The magnet 306 is activated bythe signal generated when the laser light 294 returns from the disc tothe detector of the disc reader. The moving coil 304 and the objectivelens can move within the range 308. The range 308 controls the range ofthe laser's focal zone.

The focusing servo of the present invention may move the laser's focalpoint across the laser's focal zone. The laser's focal point mayrepresent the point where the focusing servo finds a maximal amount oflight returned to the disc reader's detector. The location of thelaser's focal point therefore may be affected by the reflectiveproperties and other optical properties of various elements contained inthe optical disc assembly. For instance, where the optical disc assemblyis based on the modification of a conventional CD-R, the focal point maybe at the reflective layer which contains gold or other reflectivematerial.

More than one reflective layer, including semi-reflective layers, may beconstructed within the laser's focal zone. The reflective layers in thefocal zone can create a level of signals, the voltage of which isaffected by the position of the focal point and the reflectivity of thereflective layers. The focusing servo may be able to search for a focalpoint from which the light returned to the detector is maximal.

In a preferred embodiment, the operational structures in the opticaldisc assembly are designed to provide an improved detection for theinvestigational structures. The investigational structures may be cells,microorganisms or any other biological, biochemical, or chemicalspecimens. In one instance, the pits, lands, or wobble grooves arereconfigured to enhance tangential resolution. In another case, the pitsare shortened or the wobble is changed to provide a lower scanning speedin order to increase the radial resolution. In yet another instance, thelens layer is changed to PMMA or other material to improve opticalresponse. The lens layer may also be made thicker or thinner to make thefocal spot smaller or larger, therefore providing higher or lower energydistributions on the detector. The operational structures may beinterleaved to provide dynamic responses for enhancing imaging.

The present invention contemplates a variety of embodiments of theoptical disc assembly. For instance, the optical disc can be a forwarddisc or a reverse disc. The optical disc can have more than tworeflective layers. The operational structures can include pits, lands,grooves, wobble grooves, dye marks, chevron marks, or any combinationthereof. The operational structures may act as phase components orcreate interference patterns that provide tracking and synchronizationinformation to the disc drive. The operational structures can be in a CDformat (including a CD-R and CD-RW format), a DVD format (including aDVD-R format, a DVD-RW format and a DVD-RAM format), any combinationthereof, or any other optical disc format. The operational structurescan be physically imprinted in a surface of the operational layer, orencoded in a hologram. A custom format for operational structures mayalso be used, and the disc assembly is read by a custom decoding device.Different surfaces in the optical disc assembly can be metalized orcoated with materials with a variety of reflective properties. Thecoatings may be reflective, semi-reflective, transmissive,semi-transmissive, or anti-reflective. The materials used in the variouslayers may be dielectric or non-dielectric. Moreover, the operationallayer may be created using different processes, such as molding,electroforming, or web manufacturing.

The analyte section of the optical disc assembly can be configured toreceive an insert which holds the analyte of interest. The insert can beglass or plastic. The insert may be a sample slide regularly used forexamining biological, biochemical, or chemical samples. The insert maybe replaceable or integrated with the disc assembly. The insert may holdchemical, biological or other physical specimens. Chemical or biologicalreactions, including molecule-molecule bindings or enzymatic reactions,can be performed either on the insert or in the analyte section.Products of these chemical or biological reactions may generate opticaleffects on the incident laser light which can in turn be detected by thedisc reader. The insert may function as a cover layer or a lens layer.

The analyte section may include investigational structures which arereplaceable or integrated with the disc assembly. The investigationalstructures may contain light absorbing, light reflecting materials, oranti-reflective materials, so that they may be detectable by the opticalpickup of the disc reader. The focusing servo may search for the focalpoint with maximal return light. Such a focal point may depend on thereflectivity of the investigational structures.

The analyte section or any other layer in the disc assembly may containchannels or chambers, including microfluidic channels, through whichanalytes, investigational features or reactive components may enter orexit the analyte section. These channels or chambers may also be used tohold the analytes or investigational features for investigation.

The optical disc assembly of the present invention preferably includes alens layer. The thickness of the lens layer may be about 1.1 mm to 1.3mm, including about 1.2 mm. Such a lens layer may be used in a discassembly that is modified from a CD-type disc. The thickness of the lenslayer may also be about 0.6 mm, and can be used in a disc assemblymodified from a DVD-type disc. The refractive index of the lens layerpreferably is selected so that the laser of the disc reader can befocused in a desired manner. The lens layer may be made from a varietyof materials, including glass, plastic, PMMA, polystyrene,polycarbonate, or dyed material. The lens layer may be flat or non-flat.The lens layer may be homogeneous or non-homogenous. The lens layer maybe incorporated into the operational layer. The lens layer may containat least part of the analyte section.

The lens layer may also contain molded features, such as cavities,channels or waveguides. The lens layer may function as a cover toprotect the operational layer or other layers of the disc assembly. Thelens layer may provide physical support for other layers in the disc orfor the investigational structures or the analytes that are associatedwith the disc. The lens layer may be either laser-proximal orlaser-distal to a reflective layer or a semi-reflective layer.

In a preferred embodiment, the operational layer includes or consists ofa hologram. The operational structures are encoded in the hologram.Preferably, the hologram is a reflective hologram, and is protected by atransparent protective coating located laser-proximal to the hologram.FIG. 26 shows an optical disc assembly containing a reflective hologram512 which is protected by a transparent protective coating 514. Thehologram encodes the operational structures, such as wobble grooves,that are required by the operation of the optical disc reader. When alaser beam 516 is reflected from the hologram physical plane 512, itappears as though the encoded operational structures, such as wobblegrooves in a correct orientation, are present at the hologram imageplane 518. The hologram image plane 518 can be located substantiallyconfocal with the investigational structure 520. The investigationalstructure 520 may be positioned on the laser-distal surface 522 of thelens layer 524.

The laser beam may be focused on the image plane 518 which is shared byboth the investigational structure 520 and the encoded operationalstructures. Therefore, light from the image plane 518 may enable thedisc reader to generate both the operational signals, such as thesignals used for disc tracking, and the investigational signals that areindicative of the presence of the investigational structure. Thisfeature allows the optical disc reader to track the disc and detect theinvestigational structure concurrently and discriminably. The larger theilluminating laser spot 526 on the hologram, the better the image of theoperational structures as appeared in the image plane 518. Therefore,the laser preferably is not tightly focused on the hologram physicalplane. Typically, a portion of the hologram physical surface may besufficient to generate the entirety of the image of the operationalstructures that are interferometrically encoded in the hologram.

The hologram image plane may be positioned not concurrently with theinvestigational structure, provided that the operational structures,such as the wobble groove, can be concurrently detectable with theinvestigational structure. The image plane of the hologram may be eitherlaser-proximal or laser-distal to the investigational structure. Inaddition, the hologram image plane may be either laser-proximal orlaser-distal to the hologram's physical plane.

Preferably, the hologram is replaceable or reversibly attachable to thedisc assembly. This permits the hologram to be mass-produced using ahigh-speed holographic printing process. This also permits the re-use ofthe hologram or other parts of the disc assembly.

In another preferred embodiment, the operational structures in theoptical disc assembly are configured and organized in accordance withthe “zoned constant linear velocity” (ZCLV) format. The ZCLV format isdetailed in various industry standards, including the DVD-RAMspecification. FIG. 27 schematically illustrates the ZCLV format in acircular disc. The ZCLV disc in FIG. 27 is divided into multiple zones490 across the range 492. Although only five zones are shown in FIG. 27,actual ZCLV format discs may have different numbers of zones. Forinstance, the DVD-RAM ZCLV format allows 24 zones.

Each of the zones 490 is divided into multiple sectors 494. Inner zoneshave fewer sectors than outer zones, because the radii of inner zonesare less than the radii of outer zones. The optical disc reader can scaneach zone at a constant rate. In addition, the optical disc reader canrotate the ZCLV disc faster when it scans the inner zones than when itscans the outer zone. Therefore, the optical disc reader may maintain asubstantially constant scanning rate for all the zones in a ZCLV disc.

FIG. 28 shows an enlarged perspective view of a portion of one of thesectors of the ZCLV disc. The operational structures consist of multipletracks 498 which are arranged radially within the sector. Each track hasheader information embossed in a “pre-groove” area 500. The pre-groovearea is followed by a “wobbled land and groove” area 504 which containsthe wobble groove 498 and the wobbled land 502. Operational structuresin a ZCLV format may be holographically encoded in a hologram.

FIG. 29 shows a ZCLV-formatted optical disc assembly associated withanalytes or investigational structures 510. Analytes or investigationalstructures 510 may be deposited within the “wobbled land and groove”area 508. The embossed header information in the pre-groove area 506 canbe used to store information for identifying or controlling a desiredmeasurement of the analytes or investigational structures 510.Accordingly, different sectors in the same ZCLV disc may be used toperform different measurements or assays.

In one embodiment, the zones in a ZCLV formatted disc can be mastered insuch a way as to provide either a highly reflective surface, a partlyreflective surface, or a non-reflective surface. In each case, thepre-header information can provide tracking and location information.The pre-header information may also provide identification informationfor the nature of the zone. In addition, the pre-header information mayencode information relating to the software or firmware that is appliedto the zone. The characteristics of the investigational structures (suchas their reflectivity, absorptivity, or transmissivity) can bedetermined by the disc laser as it scans over each zone.

In a preferred embodiment, the optical disc assembly includes asemi-reflective layer which is both transmissive and reflective to thelaser light. The semi-reflective layer is usually a thin layer ofreflective or semi-reflective material, such as silicon, tellurium,selenium, bismuth, aluminum, silver, copper or other suitable metals oralloys. The thickness of the layer may range from 10 nm to 100 nm. Thereflectivity of the semi-reflective layer may range from about 18% to30%. The reflectivity may also range from about 30% to 40%. Thesemi-reflective layer may be used to coat operational structures.Whereas the reflectivity of the semi-reflective layer is low, forinstance, below about 30%, a CD-RW reader or a DVD reader preferably isused to read the operational structures that are coated with thesemi-reflective layer.

FIG. 30 illustrates a forward optical disc assembly which includes asemi-transmissive, semi-reflective layer. The semi-transmissive,semi-reflective layer 530 is placed on the operational structures whichare embossed in the laser-distal surface of the operational layer 528.Reference numeral 534 shows an operational structure coated with thelayer 530. The reflectivity of the layer 530 can return sufficient lightto render the operational structures detectable by the disc reader. Thelaser beam 532 can also pass through the layer 530 to enter the analytesection 531 which is configured to hold the analyte 538. The analytesection 533 and the analyte 538 are within the laser's focal zone 536.The laser beam 532 can be reflected back from another reflective layer533 which is laser-distal to the semi-transmissive, semi-reflectivelayer 530. This latter reflected light may carry signals indicative ofthe presence of the analyte. The laser's focus is able to roam withinthe focal zone 536.

FIG. 31 illustrates a forward transmissive pass-through disc assemblywhich permits the laser light 540 to pass through the top refractivelayer 542 to a top detector. The laser 540 is focused by the lens layer544, which is also the operational layer. The operational features arecoated with a partly reflective and partly transmissive layer 548.Reference numeral 546 shows a coated operational feature. The analyte550 is placed in the analyte section 552 which is situated between thelens layer 544 and the top refractive layer 542. Samples includingsolutions may be directed to and expelled from the analyte section 552through channels or other means. The laser's focus, driven by thelaser's focusing servo, can roam within the focal zone 554. The coatedoperational features and the analyte 550 are both placed within thefocal zone and can be detected concurrently and discriminably.

In accordance with another aspect of the present invention, the opticaldisc assembly may contain channels or chambers capable of transportinganalytes, reactive components or mediums to and from the analytesection. Analytes and other components can be mixed within thesechannels or chambers. Preferably, the analyte section also contains atleast one chamber or channel which is capable of holding the analytesfor investigation. More preferably, the operational surface contains acut-away area which may be either laser-proximal or laser-distal to theanalyte section and which may be adjacent to the analyte section. Mostpreferably, the analyte section includes a cut-away area as one surface.

FIG. 32 demonstrates a reverse disc assembly 578 including fluidicchannels. The lens layer 570 is laser-proximal to the operational layer572. The operational structures are embossed in the laser-proximalsurface of the operational layer 572. The plane 574 depicts the planeupon which the operational surface and the operational structures arelocated. The operational layer 572 contains channels 576 through whichanalytes or investigational structures can enter or exit the analytesection. The analyte section includes the channel 582 which can belocated either laser-proximal or laser-distal to the operationalsurface. The arrows associated with 576 and 582 indicate the directionof fluidic flow in the channels. The channel 582 and the operationalsurface are located within the focal zone 584.

FIG. 33 shows another reverse optical disc assembly 580 in which theanalyte section, which includes channel 588, is either laser-proximal orlaser-distal to a cut-away area. The operational surface is position onthe plane 574′. The cut-away area is in the operational surface which isthe laser-proximal surface of the operational layer 572′. The cut-awayarea preferably lacks operational structures or reflective coatings.Channels 576′ direct the fluidic flow to and from channel 588. Theoperational surface, the cut-away area and channel 588 are within thefocal zone 584′. 570′ denotes the lens layer.

FIG. 34 depicts a preferred reverse optical disc assembly. The lenslayer 590 focuses the laser beam 592 either on the reflective layer 594or on the analyte 596. The reflective layer 594 coats the operationalstructures located at the laser-proximal surface of the operationallayer 604. The analyte 596 resides in the analyte section which consistsof the chamber 598. The chamber 598 is laser-proximal to the operationalstructures and laser-distal to the lens layer. The adhesive layer 600binds the operational layer 604 to the lens layer 590. The channels 602are etched into the operational layer 604. Analytes can enter and leavethe analyte section 598 through channels 602. The operational layer 604is covered by the cover 606. The operational structures and the analytesection are with the laser's focal zone 608.

FIG. 35 demonstrates a forward optical disc assembly 618 which includesfluidic channels 616 and 620. The operational layer 610 serves as a lenslayer and is capable of focusing the laser beam 614 on the operationalstructures 612. The operational structures 612 are located at thelaser-distal surface of the operational layer 610. Channels 616,contained in the cover, can introduce analytes into the analyte sectionwhich includes the channel 620. The channel 620 can be eitherlaser-proximal or laser-distal to the operational structures. Both theoperational structures and the channel 620 are within the focal zone622.

FIG. 36 shows a forward disc assembly 621 including a cut-away area 628in the operational surface. The cut away area 628 is in the laser-distalsurface of the operational layer 610′, and preferably lacks operationalstructures or reflective coatings. Other areas in the laser-distalsurface of the operational layer 610′ are contained with the operationalstructures 612′. The channel 626 in the analyte section can be eitherlaser-proximal or laser-distal to the cut-away area 628. The focal zone622′ encompasses the operational structures 612′, the cut-away area 628,and the channel 626.

FIG. 37 illustrates a preferred embodiment of a forward optical discassembly which includes analyte channels 666. The analyte channels 666are in or immediately above the lens layer 658. These channels areconnected to the analyte section 668. The lens layer 658 is attached tothe operational layer 662 through the adhesive layer 660. The lens layer658 is laser-proximal to the operational layer 662. The operationalstructures at the laser-distal surface of the operational layer 662 arecoated with a semi-reflective, semi-transmissive layer 664. The analytesection 668 is configured to receive analytes 670, and is locatedlaser-distal to the semi-transmissive layer 664 and laser-proximal toanother reflective layer 678. The reflective layer 678, which preferablyis fully reflective, is laser-proximal to the cover 680. Laser beam 676can pass through the lens layer 658, the adhesive layer 660, theoperational layer 662 and the semi-transmissive layer 664 to focus onthe analytes 670 or the reflective layer 678. The laser 676 can bereflected from the reflective layer 678. The laser focal point can moveacross the focal zone 674. Light reflected from layer 664 may carryoperational information, whereas light reflected from layer 678 maycarry investigational information.

FIG. 38 schematically demonstrates another embodiment of a forwardoptical disc assembly. The analyte section includes an analyte channelwhich can be located either laser-proximal or laser-distal to thecut-away area 698. The cut-away area 698 is at the laser-distal surfaceof the operational layer 692. The cut-away area preferably lacksoperational structures or reflective coatings. Other areas in thelaser-distal surface of the operational layer 692 include theoperational structures 694. In FIG. 38, the cut-away area 698 islaser-proximal to the plane upon which the operational structuresreside. Channels 696 are created in the cover layer of the discassembly. Analytes or reaction components can enter or exit the analytechannel through channels 696. The laser's focal zone 693 encompasses theoperational structures 694, the cut-away area 698, and the analytechannel. One of skill in the art will appreciate that, in view of FIG.38, the cut-away area 698 may also be located laser-distal to the planeupon which the operational structures are disposed.

FIG. 39 illustrates a preferred embodiment of a forward optical discassembly including a cut-away area. The cut-away area is laser-proximalto the plane upon which the operational structures reside. Theoperational structures are positioned at the laser-distal surface of theoperational layer 724, and are coated by a reflective or semi-reflectivelayer 726. The cut-away area preferably lacks operational structures orthe coating 726. The analyte section includes a chamber 728 which isetched into the operational layer 724. The cut-away area constitutes themost laser-proximal surface of the chamber 728. Fluidic flow 730 entersinto the chamber 728 through channels 732 which cut through the coverlayer 734. A reflective layer 736 is located laser-proximal to the layer734 but laser-distal to the operational structures. The laser 738encounters and detects the first analytes 740 which are deposited on thecut-away area. The fluidic flow 730 may also mix the first analytes 740with the second analyte 742. The interaction between the analytes 740and the analyte 742 may generate detectable signals. The laser's focalzone 744 encompasses the chamber 728. As appreciated by one of skill inthe art, channels 732 may be created with the operational layer 724.

In one embodiment, the disc is a hybrid disc in that the operationalsurface includes at least two different formats of operationalstructures. For instance, the operational surface may includeoperational structures in a CD format as well as operational structuresin a DVD format. The disc reader may read both formats. Datafacilitating or regulating the disc reader to read different formats ofoperational structures may be encoded or embossed in the disc.

In a preferred embodiment, data other than operational structures can beencoded or embossed in the operational surface or other surfaces in thedisc assembly. These data may provide control information for the discreader to read or detect the investigational structures. These data mayregulate the measurement of investigational structures, for instance, bycontrolling valves which can manage fluidic flows in a fluidic circuit.These data, as well as the operational structures or other information,may be written to the disc before or after the investigationalstructures are read or detected.

The disc assembly may be used for detecting biological suspensions suchas blood, urine, saliva, amniotic fluid, cerebrospinal fluid, synovialfluid, pleural fluid, pericardial fluid, perintoneal fluid.Environmental and chemical samples may also be assayed using the discassembly. The disc assembly may include embossed features, placedfeatures or etched features.

The disc assembly may be a null type disc, a modified disc based onindustry standard disc, such as a modified CD-R or a modified CD, or adisc based on a custom format. Preferably, the disc assembly does nothave the dye layer as used in a CD-R or a CD-RW disc.

In one embodiment, data used to identify the type of the disc assemblycan be encoded in the disc assembly. For instance, a disc identificationnumber (DIN) may be digitally encoded in the disc to describe the typeof the operational layer, such as a forward wobble disc or a reversewobble disc. The DIN may also be used to describe the design of theanalyte section, the adhesive layer or the cover of the disc.

In another embodiment, the disc assembly includes an operational layer,an adhesive layer and a cover. The operational layer, the adhesivelayer, or the cover of the disc may contain channels, cavities, slots,openings, or holes. The thickness of the adhesive layer may be between25 and 500 micrometers, including within the range of about 25micrometers to 100 micrometers, such as 50 micrometers. The adhesivematerial may be pressure sensitive, and can be made from acrylic orsilicone. The cover layer may be coated with reflective materials suchas gold.

An analyte chamber may be located within the adhesive layer. Theoperational layer or the cover may contain channels that are connectedto the analyte chamber. Analytes, components reactive thereto or mediumscan be introduced through these channels to the analyte chamber.

FIG. 40 illustrates an exploded perspective view showing the principlelayers of a forward disc assembly according to one embodiment thepresent invention. The operational layer 966 is laser-proximal to theadhesive layer 958 which is laser-proximal to the cover 950. Theoperational surface 968 is coated with a semi-reflective,semi-transmissive layer. The operational layer 966, the adhesive layer958 and the cover 950 includes a central hole 964, 962 and 954,respectively. The disc assembly can be coupled to a disc reader throughthese holes, for example, by clamping to a motor shaft. The adhesivelayer includes an opening 960, which forms an analyte chamber when theselayers are assembled together. The adhesive layer has a depth of about100 micrometers. Investigational structures can be manipulated orretained in the analyte chamber formed by the opening 960. The cover 950includes the ports 952 and 956. When the disc is assembled, thesechannels are connected to the analyte chamber 960. Investigationalstructures or other reaction components may enter or exit from thechamber 960 through the ports 952 and 956. Both the operational layerand the cover layer may be made from polycarbonate. The laser beam maypass through the disc assembly and be read by a top detector.Alternatively, a reflective layer may be coated at the laser-proximalsurface of the cover 950 so that the laser beam can be reflected backtherefrom.

As appreciated by one of skill in the art, a reverse wobble discassembly can be similarly constructed as shown in FIG. 40. In addition,channels or openings, through which investigational structures orreaction components can be introduced into the analyte section, may becreated in the operational layer. Operational structures may be createdin the laser-proximal surface of the cover layer 950.

Channels, cavities, inlet and vent ports, or other structures in theoperational layer, the adhesive layer or the cover may be in a varietyof configurations. FIG. 41 shows an operational layer 902 which has fourslots 900. FIG. 42 shows an adhesive layer 904 which has a series ofopenings 906. These openings can form analyte chambers in the assembleddisc. These different chambers may be connected to different channelslocated in either the cover layer or the operational layer. Theassembled disc may perform different assays in different analytechambers.

Data encoding design information that identifies the type of the discassembly may be stored in the disc assembly and readable by the discreader. Such information may also be printed on a surface of the discassembly. For instance, a disc identification number (DIN) can be usedto identify the type of the disc assembly. The number may includealphanumeric characters that are subdivided into different fields. Onefield may describe the main specifications of the operational layer. Themain specifications include whether the disc is a reverse disc or aforward disc, and the particular disc design type for the operationallayer. The main specifications may also include an identification numberfor the master of the operational layer. A second field of the DIN mayrepresent various modifications or other variables of the operationallayer. The variables include the placement of the cut-away areas and thenumber of analyte chambers. In addition, the second field of the DIN maydescribe the position of the adhesive layer or techniques or materialsused in making the disc assembly. The designs of the cover layer mayalso be described in the second field. A third field may include, whichcan be used to identify each disc. This serial number may be in theorder of manufacture of the disc.

It should be understood that the above-described embodiments are givenby way of illustration, not limitation. Various changes andmodifications within the spirit and scope of the present invention willbecome apparent to those skilled in the art from the above description.In addition, the reader's attention is directed to the provisionalapplications from which the present application claims priority. Thecontents of all these provisional applications are incorporated hereinby reference.

1. A bio-disc assembly comprising: a circular adhesive layer comprisingone or more apertures; a circular top layer; and a circular bottomlayer, wherein the circular top layer and the circular bottom layer arepositioned on either side of the adhesive layer and coupled together viathe adhesive layer, wherein the top layer comprises one or more holesthat are aligned with respective apertures of the adhesive layer so thatthe bio-disc is configured to receive biological samples into theapertures of the adhesive layer through respective holes of the toplayer; wherein at least one of the top and bottom layers comprisesdigital bio-disk identification information that is readable by anoptical bio-disc reader, the digital bio-disk identification informationcomprising first information indicating whether the bio-disc is areverse disc or a forward disc, second information indicating at leastone of position information regarding the apertures in the adhesivelayer and a number of apertures in the adhesive layer, and thirdinformation comprising a bio-disc specific serial number, wherein thedigital bio-disk identification information allows a bio-disc reader tolocate and analyze samples in the one or more apertures of the adhesivelayer.
 2. The bio-disc assembly of claim 1, wherein the bio-disc readercomprises a CD reader or a DVD reader.
 3. The bio-disc assembly of claim1, wherein the holes of the top layer are smaller than the apertures ofthe adhesive layer.
 4. The bio-disc assembly of claim 3, wherein atleast one of the apertures of the adhesive layer is in fluidcommunication with two or more holes in the top layer.
 5. The bio-discassembly of claim 4, wherein a first of the two or more holes comprisesa sample inlet port configured to receive a sample into the at least oneaperture and a second of the two or more holes comprises an exhaust portconfigured to allow air in the aperture to escape the bio-disc assemblyas the sample is received into the aperture.
 6. The bio-disc assembly ofclaim 1, wherein the holes of the top layer are substantially circularand the apertures of the adhesive layer extend from near a centralportion of the bio-disc towards an outer portion of the bio-disc.
 7. Thebio-disc assembly of claim 6, wherein a portion of the apertures nearthe central portion of the bio-disc is wider than a central portion ofthe apertures.
 8. An optical bio-disc assembly configured for placementin an optical bio-disc reader such that characteristics of one or morebiological samples placed on the optical bio-disc may be determined bythe optical bio-disc reader, the optical bio-disc assembly comprising:one or more substantially circular layers that are coupled together inan arrangement that forms a sample analysis portion comprising one ormore sample inlet ports that are in fluid communication with respectivesample chambers, wherein at least one of the substantially circularlayers comprises disc identification information digitally encoded inthe at least one layer, the disc identification information beingconfigured for reading by an optical disc reader, wherein the one ormore substantially circular layers comprise an operational layercomprising a wobble groove, an adhesive layer, and a cover layer,wherein the adhesive layer comprises a plurality of apertures such thatwhen the adhesive layer is sandwiched between the operational layer andthe cover layer the plurality of apertures form a plurality of chamberssuitable for containing biological samples.
 9. The optical bio-disc ofclaim 8, wherein the disc identification information further comprisesan indication of whether the optical bio-disc is a forward wobble discor a reverse wobble disc.
 10. The optical bio-disc of claim 8, whereinthe adhesive layer has a thickness in the range of about 25 to 500micrometers.
 11. The optical bio-disc of claim 8, wherein the adhesivelayer comprises one or more of acrylic or silicone pressure sensitivematerials.
 12. The optical bio-disc of claim 8, wherein the discidentification information identifies characteristics of the wobblegroove of the operational layer.
 13. The optical bio-disc of claim 8,wherein the disc identification information identifies a master of theoperational later.
 14. The optical bio-disc of claim 8, wherein at leasta portion of the wobble groove is covered with a reflective layer thatis configured to reflect laser light from the optical bio-disc reader.15. The optical bio-disc of claim 14, wherein the reflective layercomprises cut-away portions that are aligned with the respective samplechambers.
 16. The optical bio-disc of claim 15, wherein the discidentification information indicates a location of the cut-awayportions.
 17. The optical bio-disc of claim 8, wherein the discidentification information comprises an indication of one or more designfeatures of the sample analysis portion of the optical bio-disc.
 18. Anoptical bio-disc reader comprising: a mounting structure configured toengage a central aperture of a multi-layer optical bio-disc, the opticalbio-disc housing one or more biological samples; a laser assemblyconfigured to project a laser beam towards a surface of the opticalbio-disc; one or more sensors configured to determine digitalidentification data encoded in the optical bio-disc, the digitalidentification data indicating whether the optical bio-disc comprises aforward wobble disc or a reverse wobble disc; a sample analysis moduleconfigured to select a first one or more algorithms for determiningproperties of samples on the optical bio-disc in response to determiningthat digital identification data indicates the optical bio-disccomprises a forward wobble disc, the sample analysis module beingfurther configured to select a second one or more algorithms fordetermining properties of samples on the optical bio-disc in response todetermining that digital identification data indicates the opticalbio-disc comprises a reverse wobble disc.
 19. The optical bio-discreader of claim 18, wherein the optical bio-disc reader is configured toread digital data from one or more of CDs and DVDs.